Telephone system



Aug 6, 1929.,

J. WICKS 1,723,224

TELEPHONE SYSTEM 15 Sheets-Sheet 1 Original Filed Aug. 7, 1925 fi mm J. WHGKS 3132359224? TELEPHONE SYSTEM Original Filed Aug. 7, 1925 15 Sheets-Sheet 2 Aug. 6, 1929.. J. WICKS TELEPHONE SYSTEM 15 Sheets-Sheet 5 Original Filed Aug. '7, 1925 Inuan m:

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TELEPHONE SYSTEM Original Filed Aug. '7, 1925 15 Sheets-Sheet 7 'Wamw TELEPHONE SYS TEM Sheets-Sheet Original Filed Aug. 7',

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Aug WEE J. WHCIMS TELEPHONE SYSTEM Original Filed Aug. '7, 1925 15 Sheets-Sheet l 2 a J. WICIKS TELEPHONE SYSTEM Original Fi led Aug. 7, 1925 l5 Sheets-Sheet l 3 2 mg. fi fi J.VVICKS TELEPHONE SYSTEM Original Filed Aug. '7, 1925 3,5 Sheets-Sheet 14 wwww mww n J0 h m Mi 51m K96. J, wlc s L723224 TELEPHONE SYSTEM Original Filed 1925 15 Sheets-Sheet 1s AOHN "WICKS, h OAK; PARK, ILLINUIS, ASSIGNOR, lBY E$NE AhSlH-NMEN'lfi, LUO AUTU- IMATIC EIAECTRIC- llh'l'fit, 01E GHIGAGO, ILLINOIfi, A CURJPU'JLIQN 01E DELAWARE.

TELEPHONE fiYfiT.

Application filed August t, 1925, Serial No. races. Renewed November 10, 19%.

lhe present invention relates to telephone systems in general, but as regards a number of its objects and features, it is concerned more particularly with automatic telephone t systems of the so-called inverted type in A05 andNo. 1,681,913 patented April 2A, 1928 and August 21, 1928 respectively.

Une object of the invention is the pro vision of arrangements whereby the switchover operation (which takes place automatil cally when the final digit in a given number is dialled) is used to bring about the switchthrough operation in the directors (which are employed to receive the number dialled by the calling subscriber and to route the he call to the desired office and finally to the desired line). The utility of this arrangement lies in the fact that, with the switchthrough operation of the director under the control of the switch-over operation in the switch train, the directors may housed in handling calls in which the telephone numbers do not contain a uniform number of digits without adding special apparatus to the director in order to cause it to be switched through and freed from the connection at one point or another in accordance with the number of digits in the telephone numbers.

Another object of the invention is the production of a new and improved toll service trunking system to operate in conjunction with the present inverted system to enable toll operators to complete the connections to the subscribers lines through. switches operating along the same line as the other At awitchesin the system and to be able to retain the necessary supervision overthe connection and to control the starting of the application of ringing current to the called line.

Another object more or less closely associated with the preceding one is the production of an arrangement whereby the intermediate selectors and the connectors in a given ofiice may form apart of the toll service trunking W system as well as a part of the regular subscriber-to-subscriber trunking system, and to this end certain novel circuit arrangements have been devised to permit the intermediate selectors and the connectors to be used in both systems, without unnecessarily complicating these switches.

According to another feature, a new and improved rotary connector has been provided for use in the inverted system to take care of the situation in which a certain subscriber desires several lines having a common call number.

Another object is the production of an arrangement whereby-two otlices, one containing switches operated according to the inverted system, and the other containing switches operated according to the non-inverted system, may both form part of the same multi-otlice trunking system, and to this end an incoming selector has been provided in the inverted office to operate responsive to the first series of impulses received from the non-inverted system, to repeat the remaining impulses to the other selectors and to the connectors, to supply talking battery to the called line, and to reverse battery to the non-inverted ofiice when the called sub scriber responds.

Another object of the invention is the provision of a new and improved impulse repeating arrangement to enable impulses to be repeated satisfactorily over long trunk lines. To this end a repeater has been provided for insertion into an outgoing trunk line when the trunk line is of great length, together with certain modifications inthe distant incoming selector to adapt it to respond to the reversals of current in the trunk line brought about by the repeater to operate the switches in the distant ofice.

Another object of the invention is the production of an arrangement for completing calls to an operators position and for auto matically controlling the first selector repeater from the trunk line leading to the operators position to switch through and cut-off all the bridges from the talking circuit and to hold up dependent upon ground supplied to the release trunk conductor at the operators switchboard.

There are of course a number of objects and features subsidiary to the foregoing which may be understood best from a further perusal of the specifications.

Referring now to the accompanying drawings comprising Figs. 1-17, Figs. 1-16 show by means of the usual circuit dia rams a sufiicient amount of equipment emplbyed in a telephone system embodying the princlples of the invention to enable the invention to be understood, and Fig. 17 is a diagram showing how the sheets of drawings on which Figs. 1-l6 appear should be arranged in order to be understood best.

Fig. 1 shows a three conductor toll service trunk extending from the jack J at the toll board to the selector S located in the same ofiice as the toll board. This drawing shows also the cord circuit CC which is one of the cord circuits used by the toll operator to complete connections to the toll service trunks through the jacks such as J.

Fig. 2 shows the transmission selector repeater on the incoming end of the inter-office trunk line comprising conductors 9 and 10 and accessible to the selector S, Fig.1 This selector repeater is of a special deslgn so as to give theoperator the correct supervision and so as to enable the operator to control the starting of the application of ringing current to the called line.

Fig. 3 shows an intermediate selector which is the term applied to the simple selectors coming in the switch train follow ing a battery feed selector in the same oflice. This intermediate selector is accessible to the transmission selector repeater Fig. 2 and to the incoming selector repeaters shown in Figs. 11 and 12. This selector has the usual line and release trunk conductors and it also has an extra conductor 160 coming into it from the transmission selector repeater and passing out through the wiper 243 for the purpose of controlling the ringing operation of the connectors. The conductor 160 accordingly is local to the transmission selector repeaters and does not multiple down to the incoming selector repeaters shown in Figs. 11 and 12.

Fig. 4 shows a combination toll and regular connector which is accessible to the intermediate selector shown in Fig. 3, and which has access to the line of substation A an to other lines.

Fig. 5 shows a connector similar to the connector of Fig. 41-, except that the function performed by relays 303 and 307 of Fig. 4

is performed by relay 406, Fig. 5, with theductors 7 97-7 98. This trunk circuit is used for extending connections to the toll recording operator and it brings about-the operation of the switch-through relay 721 of the first selector repeater, Fig. 8, so as to remove all bridges at the first selector repeater to give a clear talking circuit through to the manual switchboar Fig. 8 shows the first selector repeater which is accessible to the line switch LS associated with the line of the substation A. This selector repeater is provided with the necessary arrangements for feeding talking battery to the calling subscriber in all cases and to the called subscriber on local calls. It is also provided with the necessary arrangements for cooperating with the director shown in Figs. 13-16.

Fig. 9'- shows a reverse batteryrepeater which responds to the impulses received by the line relay 803 to reverse the direction of the current flow over the conductors 818 and 819 to operate the electro-polarized relay 1001, Fig. 11, to bring about the operation of the automatic switches in the distapt office.

Fig. 10 shows a reverse battery repeater somewhat similar to the one shown in Fig. 9, but difiering somewhat in detail as will be pointed out hereinafter.

Fig. 11 shows an incoming selector repeater accessible to the first selector repeater shown in Fig. 8 through the trunk line comprising conductors 818 and 819. This incoming selector repeater is designed to operate responsive to the reverse battery impulses transmitted by the reverse battery repeaters shown in Figs. 9 and 10. It also supplies talking battery to the called line and it controls the switch-over and metering operations of the first selector repeater shown in Fig. 8.

Fig. 12 shows an incoming selector repeater which performs functions similar to those of the incoming selector repeater shown in Fig.

- 11 as regard the supplying of talking battery to the called line, but instead of being accessible toa first selector repeater operating in the inverted system, it is accessible to an ordinary two wire selector in a distant ofiicc through the medium of the usual outgoing repeater.

Figs. 13-16 taken together show a director selector individual to the first selector repeater, Fig. 8, and one of the directors accessible to the director selector.

The portion of the director shown in Fig; 13 comprises the sequence switch S which is used to distribute the? various series of impulses received by the director to the various operating magnets of the registers concerned. Thls drawing shows also the sequence switch vS which is used to control the various steps in the sending operation as will hereinafter appear.

Fig. 14 shows the director selector which tilt responds to the first ollice digit to select a director in the proper group. This drawing shows also the sending portion of the director, which comprises the pick-up and stop relays 124:6 and 12%, together with the sending switch Sh which counts the impulses as they are being transmitted and consequently terminates the transmission when the required number has been transmitted in a given case.

' The portion of the director shown in Fig.- 15 comprises the office register UR which responds to the second and third oihce digits, together with the intermediate distributing itrame lllDF through the medium ot which the code digits transmitted on calls to any oflice may be alteredat will.

The portion of the director shown in Fig. 16 comprises the four digit registers DR-1- ,DR- t which are used to register the tour subscriber digits in a number after the office digits have been talren care of by the director selector, Fig. 1d, and by the ollice register OR Fig. 16.

Regarding the mechanical construction of the apparatus shown, the various selectors, selector repetiters and connectors are me -chanically of the well-known vertical and rotary type of switch in which the bank contacts are arranged in horizontal rows or levels. The otliee register Old, Fig. 15, is also of this type.

'The various line switches such as LS are mechanically of the well known rotary type of switch-in which the wipers are advanced in one direction only and are advanced upon the back stroke of the associated stepping magnet. The same is true of the sequence switch S, Fig. 13, and the sending switch @S, Fig. 14/

The sequence switch S, Fig. 13, is a switch of a simple type in which the wipers are advanced in one plane only by the operating magnet 1205 and are restored to their normal position by the release magnet 1206 under the control of the off-normal contacts 1207. The digit registers DR-1-Dlt-d, Fig. 16, are of the same type of switch mechanically.

The invention having-been described generally, a detailed description of the opera tion of the apparatus shown will now be given. For this purpose it will be assumed that the subscriber at substation A, desiring to converse with the subscriber at substation A, removes his receiver and dials the digits in the number of the subscriber at substation A. 7

Call from substation Al to substation; A.

When the receiver is removed at the substation A. a circuit is closed over line conductors 701 and 702 for line relay 7 04 of the line switch LS. Line relay 704: energizes over the calling line and places ground on the associated private normal conductor 718 leading to the banks ot the connector switches having access to the line of substation A, thereby making this line busy to those connectors, and also closing a circuit through the combined switching and cut-oil relay 703 and the motor magnet 705. Line relay lalso at armature 720 connects test wiper 711 through armature 707 and its resting contact to the junction of relay 7 03 and magnet 7 05. Accordingly, if the trunli: upon which the wipersof the switch are standing is busy the ground potential encounteredby test wiper 711 shunts relay 703 and prevents it from energizing and affords a direct circuit for the self interrupting stepping magnet 70). Accordingly stepping magnet705 operates in a buzzer-likemanner to advance the wiper 710-713 in search of anidle trunk line.

When an idle trunk line is reached, the stepping magnet 705 ceases to operate, and relay 703, being no longer short circuited, energizes in. series with stepping magnet- 705, which however does not operate at this time on account of the relatively high resistance Y ot relay 703. Upon operating, relay 703 disconnects test wiper 711 from the junction olits own winding and that oi magnet 705- and connects it to the grounded private normal conductor 718, thereby extending ground to the release trunk conductor 715 of the seiaed trunlr; connects up the meter operating wiper 712 at armature 708; and at armatures 700 and 709 disconnects conductors 7.01 and 702 from line relay 70 i and ground and extends them by way of wipers 710 and 718, conductors 71d and 717, and the normally closed contacts controlled by armatures 751 and tea to the windings of line relay 722 of the first selectdi repeater. Line relay 722 now energizes over the calling line and. closes at armature 7 56 a circuit for the release relay 723. Relay 723 energizes and places ground on the local-ground supply conductor 748 at armature 758, prepares the vertical magnet circuit at armature 759:; and at armature 7 57 places ground through the low resistance lower winding of relay 721 on the release trunk conductor 715 to maintain the switching relay 7 03 of the line switch. LS operated and to maintain the calling line guarded after the falling back of the slow acting line relay 7 04. Although the current for holding switching relay 703 operated is obtained through the lower winding out relay 7 21, the proportion between the windings of the two relaysis such that relay 721 is not operatively energized at this time, nor is it operatively energized in case-several other holding relays obtain their current through its lower winding. The tunetion of this winding will be brought out hereinafter.

The calling subscriber now manipulates his calling device in accordance with the first digit in the desired number, being inllld lldll formed of the condition of readiness of the exchange apparatus by the dial torie current transmitted to the calling line from the dial tone lead, Fig. 14, through the resting contact and armature 1325, conductor 1301, working contact and armature 771 of relay 728, which is energized from release trunk conductor 715, and the resting contact and arniture 782.

When the calling subscriber turns his calling device, the circuit of line relay 722 of the first selector repeater is interrupted a correspoding number of times. Each time it falls back, line relay 722 closes at armature 756 a circuit for the vertical magnet 1319 of the director selector, Fig. 14 as follows: from ground by way of armature 753 and its resting contact of relay 721 of the first selector repeater, armature 7 56 of line relay 722 and its resting Contact, armature 759 and its working contact, armature 788 and its resting contact, conductor 1302, armature 1324, relay 1312, and vertical magnet 1319 to battery. By the operation of vertical magnet 1319 the wipers 13291331 are raised step by step and come to rest opposite the desired level of bank contacts. Relay 1312 is energized in series with vertical magnet 1319 upon the first impulse of current being delivered to the latter, and is maintained energized throughout the series. of impulses to the vertical magnet on account of the fact that it is slow acting. At armature 1323 relay 1312 prepares a circuit for the stepping relay 1311 and opens a point in the circuit of rotary magnet 1314. As soon as the off-normal contacts 1315 operate, as they do upon the completion of the first vertical step, the circuit of relay 1311 is completed as follows: from ground by way of the grounded conductor 748, Fig.8, resting contact and armature 780, conductor 1304, working contact and armature 1 323, olfnormal contacts 1315, and stepping relay upon rotary magnet 1314 energizes and ad vances the wipers 13291331 into engagement with the first set of bank contacts in the selected level, and near the end of its stroke, it opens at interrupter contacts 1306 the locking circuit of relay 1311, whereupon relay 1311 falls back and opens the circuit of rotary magnet 1314 at armature 1322,

and opens a further point in its own locking circuit at armature 1321. Rotary magnet 1314 now falls back and closes its interrupter contacts 1306 again. I

The further operation depends upon whether the first set of contacts in the selected level is busy or idle. If this set of contacts is idle, switching relay 1313 energizes right away, seizing the associated director. Assuming, however, that the director associated with this set of contacts is busy, there is a grounded potential on the test contact encountered by test wiper 1330, with the result that switching relay 1313 is shunted and-does not operate and that a circuit is closed for stepping relay 1311 which -energizes and closes a. circuit for rotary magnet 1314 with the result that the wipers 13291331 are advanced another step.

This alternate operation of relay 1311 and rotary magnet 1314 continues until an idle set of bank contacts is reached, which set it will be assumed is the one comprising conductors 1332-4334. \Vhen this idle set of bank contacts is reached, stepping relay 1311 is unable to operate over test wiper 1330, and switching relay 1313 (being no longer short circuited) energizes in series with relay 1311, which latter relay is unable to energize on account of the relatively high resistance of relay 1313. Upon energizing, relay 1313 opens a point in the test circuit and grounds the wiper 1330 at armature 1326; opens a point in the circuit of release magnet 1318 at armature 1327; and at armature 1325 disconnects the dial tone lead from conductor 1301; at armature 1324 disconnects the impulse conductor 1302 from the local vertical magnet circuit and extends it by way of the working contact of armature 1324 to wiper 1329; and at armature 1323 connects up wiper 1331.

In the seized director, the switch-throughcontrol relay 1345, which is associated with the outgoing control conductor 1337, now energizes in series with the lower Winding of relay of the first selector repeater, Fig. 8, over the following circuit: from ground by way of the Lower winding of the impulse relay 729, Fig. 8, normally closed contacts controlled by armature 784, conductor 1305, armature 1328 and its working contact, wiper 1331, bank contact 1334, conductor 1337, restin contact and armature 1351 in multiple with the sending contacts 1361, and

'the switchgthrough control relay 1345 to bat tery. The two relays 729 and 1345 energize in series over this circuit and relay 1345 opens at armature 1350 a point in the switchthrough circuit so as to prevent a premature. operation of the switch-through relay 730 of the first selectorrepeater. Fig. 8.'whcn the stop relay 1347 of the sender operates.

In the first selector repeater, relay T29,

upon energizing, prepares a locking circuit for its upper winding at armature 772, and at armature 77 3 opens a'point in the circuit of vertical magnet 736 and closes a circuit for relay 726 as follows: from ground by Way of the grounded conductor 748,-resting contact and armature 780, armature 787 and its resting contact, armature 773 and its working contact, normally closed ofldiorlnal springs controlled by spring 735, and relay 726 to battery. Relay 726 now energizes and prepares a circuit for stepping relay 727 at armature 764, and at armature 766 prepares a circuit for vertical magnet 736.

In the seized director, release relay 1344 energizes through the grounded test wiper 1330 of the director selector, bank contact 1333, and the release trunk conductor 1336 and removes ground from the release conductors 1342 and 1358.

The calling subscriber now manipulates his calling device in accordance with the remaining digits in the desired number, and when the next digit is dialled, the resulting impulses of current transmitted by line relay 722 of the first selector repeater are transmitted over the previously traced circuit I through conductor 1302 to armature 1324 of'the director selector and thence by way of the working contact of armature 1324, wiper 1329, bank contact 1332, conductor 1335, slow acting series relay 1201, Fig. 13, distributing wiper 1210 of the sequence switch S, vertical magnet operating conductor'1221, and vertical magnet 1402, Fig. 15, ot the ottice register OR to battery. Accordingly, the vertical magnet 1403 operates to raisethe wipers 1411-1414 of the office register OR to a position opposite the desired level of bank contacts of the oilice register. Relay 1201 is energized in series with vertical magnet 1401 on the first impulse of current and, being slow acting, maintains its armature 1203 attracted throu hout the vertical operation. Upon energizing, relay 1201 closes a circuit for the associated slow acting relay 1202 which operates and prepares at armature 1204 a circuitt'or magnet 1205 of the sequence switch ,8.

At the end of the digit, relay 1201 falls back and completes-at armature 1203 the cirunit through armature 1204 and its working contact for stepping magnet1205 whereupon the wiper 1208 and 1210 are advanced one step. The slow acting relay 1202 falls back shortly and opens the stepping magnet circuit at armature 1204.

When the next digit is dialled, theresulting series of impulses is transmitted over the circuit previously traced to the wiper 1210 oil the sequence switch 555, and from thence over the rotary magnet operated conductor 1222 to the rotary magnet 1402 of the oifice register Olt. ltotary magnet 1402 operates to advance the wipers ,ot the ofice register into engagement with the desired set of bank contacts, which set it will be assumed is the one comprising contacts 14211424.

The wipers 1208 and 1210 of the sequence switch S are advanced at the end of the rotary movement in' the manner above described, wiper 1210 extending the operating conductor to conductor 1231 and wiper 1208 connecting the interrupter 1209 to the start conductor 1341 leading to the sender, Fig. 14. This latter. operation results in the starting of the sender to transmit the necessary digit combination to trunk the call to the called ofice, as will be later explained.

When the next digit is dialled, the resulting impulses of current are transmitted over the conductor 1231 to stepping magnet 1501 of the digit register Dlt-1 with the result that the Wiper of this register is set on the corresponding bank contact.

Similarly, the next three series of impulses are transmitted over conductors 12321234 to the stepping magnets of the digit registers DR DR respectively, with the result that their respective wipers are set on the cor responding bank contacts.

The wipers 1208 and 1210 of the sequence switch S of course are advanced inthe usual manner at the end of each series of impulses, and at the end of the last series, wiper 1210 advances to a dead contact and the. Wipers remain in this position until the director is released.

Reverting now to the point at which the interrupter 1209 is connected to conductor 1341 at wiper 1208 of the sequence switch 3 at the end of the setting of the ofice register UR, upon the first subsequent clo'- sure of the interrupter 1209 an impulse of current is transmitted over conductor 1341 and through the resting contact and armature 1356 to the stepping magnet 1360 01 the sending switch SS.- Magnet 1360 thereupon energizes preparatory to advancing the wip ers 1363 and 1364 and it falls back and ad vances these wipers one step when the impulse is terminated. Wiper 1364 engages a dead contact, but wiper 1363 encounters a grounded contact, closing a circuit for the pickup relay 1346. Pickup relay 1346 energizes and places a local ground on the release trunk conductor 1336 so asto insure the holding of the director until the transmission of the digit is completed; closes at armature 1353 a circuit through armature 135'? and. its

resting contact and over conductor 1343 tor the stepping magnet 1213 of the sequence switch 8", which magnet energizes preparatory to advancing the wipers 1211 and 1212; and at armature 1351 itremoves the shunt from around the sending contacts 1361 oil: the sending switch 3%. n

Accordingly, on each subsequent energi ration of stepping magnet 1360 of? the an c uenee switch .38, the outgoing control err? 

